1. Field of the Invention
The present invention relates to railroad cross ties and, more particularly, composite railroad cross ties and methods of manufacturing composite rail road cross ties.
2. Description of the Related Art
Railway tracks are typically supported on a plurality of individual cross ties. Wooden cross ties are one of the most common types of railroad cross ties. When using a wooden cross tie, the railway tracks are typically secured to the cross tie using tie plates and spikes that are driven into the cross tie. Various other materials, however, are also used to form railroad cross ties. For example, concrete and steel are also used to form cross ties.
Composite railroad cross ties which utilize recycled plastic resins are also known in the art. One example of a composite railroad cross tie is disclosed in U.S. Pat. No. 6,179,215 B1 the disclosure of which is incorporated herein by reference. Composite cross ties often include an inner core that includes a steel reinforcing member encased in concrete and an outer resinous casing surrounding the inner core. The outer casing may be formed out of a material that includes recycled plastic resins. The outer casing provides protection against adverse weather conditions for the inner core. The formation of the outer casing on the inner core, however, may leave the two end surfaces of the inner core exposed. Polymeric end caps can be placed on the two exposed end surfaces of the cross tie in an effort to protect these end surfaces from adverse weather conditions. It has, however, proven difficult to secure polymeric end caps on the exposed end surfaces of composite railroad ties in a reliable manner.